1. Field of the Invention
The present invention relates to a method for making a mobile-to-mobile wireless data communication, and more particularly, to a method for making a mobile-to-mobile wireless data communication in PCS(Personal Communication Services)/digital cellular mobile telecommunication system.
2. Background of the Related Art
Data communication between a mobile data terminal having a mobile terminal, such as a mobile phone and a data terminal such as a mini-computer connected together, and a wire data communication network, such as a PSTN(Public Switched Telephone Network), has been done using IWU (Interworking Unit). And, data communication between the mobile data terminals within a wireless mobile communication network is also done using the IWU. The IWU interconnects various independent communication networks to extend an overall communication range, for providing services that can not be provided by the independent networks. That is, the IWU serves to match protocols between wire data communication networks such as PSTN""s and/or wireless data terminals connected to the wire data communication networks. For example, the IWU allows an E-mail or internet by means of a mobile terminal such as a mobile phone connected to a portable mini-computer, or communication between an acoustic coupled terminal connected to a mobile phone and a computer in a packet switching network.
FIG. 1 illustrates a configuration of a related art wire/wireless data communication network including an IWU.
Referring to FIG. 1, the related art wire/wireless data communication network is provided with a plurality of mobile data terminals (or mobile hosts) 11(11A-11D) each having a mobile terminal MT1 or MT2 connected to a data terminal TE1 or TE2, such as a lap top, a palm top, or a minicomputer, a plurality of BTS""s (Base Stations) 12a-12d for relaying communication between the mobile data terminals 11, a plurality of BSC""s (Base Station Controllers) 13a and 13b for controlling an overall management of the BTS""s 12a-12d, a wireless data communication network 10 having a plurality of MSC""s (Mobile Switching Centers) 14 for providing a contact point of a user traffic in making a communication between two mobile data terminals in mobile communication networks of its own or other than its own, a wire data communication network 20 having a plurality of wire data terminals such as computers each with a wire telephone 23 connected thereto through a modem 22, an internet network 30, a personal data network 40, and an IWU 50 for interconnecting the networks 10, 20, 30, and 40.
A related art method for making a data communication between a mobile data terminal 11c wireless connected to a wireless data communication network 10 and a wire data terminal(the computer 21 connected with the wire telephone 23 connected to the wire data communication network 20 will be explained with reference to FIGS. 3-4. FIG. 2 illustrate an architecture showing a circuit data service communication protocol in a mobile communication system given in IS-99 and IS-707 recommendations. What is shown in FIG. 2 is a communication protocol only on a transmission side with reference to the IWU, while omitting a receiver side as the receiver side communication protocol architecture is symmetry with respect to the IWU. This communication protocol architecture is mostly used in a wireless circuit data service. First, under a condition that one mobile data terminal 11c is provided by connecting a transmission side data terminal TE2 and a mobile terminal MT2 both in the wireless data communication network 10, a user makes a communication with an AI (application interface) layer in the mobile terminal MT2 using an AT instruction word through a screen given on a data terminal TE2, to set up a data communication mode of the mobile data terminal 10c and communication parameters. Then, the user calls a wire data terminal (or a wire host) in the wire data communication network 20 using an ATD originating instruction word. When the user of the mobile data terminal 11c called a counter part using the ATD originating instruction word, the originating function of the mobile terminal MT2 demands a call connection to the mobile switching center 14b through pertinent base station 12c inclusive of a data service option n required from the CAI layer in the mobile terminal MT2. Then, detecting the data service option n, the mobile switching center 14b sets up a RLP (Radio Link Protocol) for use in data link of the mobile terminal MT2 between the mobile terminal MT2 and the base station 12c for execution of the call from the mobile data terminal 11c. The mobile switching center 14b connects the data terminal TE2 to the IWU 50 through a mobile data path and a signalling path shown in FIG. 3. Once the data path between the mobile terminal MT2 and the IWU 50 is established, a data communication protocol layer is set up between the mobile terminal MT2 and the IWU 50. Accordingly, the AI layers of the mobile terminal MT2 and the IWU 50 are connected to each other to process the AID originating instruction word the user applied to the data terminal TE2 in the AI layer of the IWU 50, so that the IWU 50 calls the wire data terminal 21 connected to the PSTN through the signalling path. Then, the modem 22 connected to the IWU 50 is activated to connected a circuit to a modem of the counterpart through a PSTN path, opening a communication between the wireless data terminal TE2 and the data terminal 21 in the wire data communication network 20 and allowing a communication between both parties. On the other hand, in a case of data reception, when the wire data communication network 20 calls the mobile data terminal 11a-11d with a subscriber identification number of the mobile terminal MT1 or MT2, the mobile switching center 14b calls the mobile terminal MT2 through the base station 12a-12d. When the mobile terminal MT2 gives a response in the data service option n, the mobile switching center 14b connects the IWU 50 to a relay layer for the mobile data path and the wire data communication network 20 is connected to the IWU 50. In this instance, the base station 12 activates the RLP layer of the mobile terminal MT2 for making a both way communication of the mobile data terminal 11c and data terminal connected to the wire data network 20 the same as the case of calling signal.
However, this related art is developed mainly aimed for data communications between a data terminal and a data terminal in a wire network. Accordingly, the aforementioned related art has been applied even to a wireless data communication between data terminals. That is, in order to conduct a wireless communication between data terminals using communication standards such as IS-99 or IS-707, the IWU should set up a call for a reception terminal because a communication protocol with the IWU should be used. In this instance, one more modem in the IWU should be occupied and an additional path from the IWU to the mobile switching center should be used.
Accordingly, the present invention is directed to a method for making a mobile-to-mobile wireless data communication in PCS (Personal Communication Services)/digital cellular mobile telecommunication system that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.
An object of the present invention is to provide a method for making a mobile-to-mobile wireless data communication in PCS (Personal Communication Services)/digital cellular mobile telecommunication system which allows a direct communication without occupying an IWU.
Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.
To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, the method for making a mobile-to-mobile wireless data communication includes the steps of (1) transmitting an originating instruction for a terminating mobile data terminal as an originating mobile data terminal sets up a service mode, (2) making a communication using a first radio link protocol (RLP) set up between the originating mobile data terminal and a base station/mobile switching center, (3) calling the terminating mobile data terminal through an identification number of the originating mobile data terminal and a service option as the originating instruction is executed, (4) informing a signal responding to the call to the originating mobile data terminal, (5) making a communication using a second RLP set up between the terminating mobile data terminal and the base station/mobile switching center, (6) setting up protocol layers in succession, the protocol layers having levels higher than levels of the first, and second RLP""s, and (7) executing a wireless data communication between the originating, and terminating mobile data terminals.
Though the present invention having the aforementioned features uses a basic data communication protocol the same as the related art protocol used in communication between a mobile data terminal and a data terminal in a wire data communication network as it was, a service option n operative in actual service and an operation of an AI layer in the mobile terminal are changed, and no interworking unit is involved. And, information on a state of the terminating terminal of being busy or giving no response can be transmitted quickly to the originating mobile data terminal in a form of a control signal through a signalling channel between the mobile data terminal and the base station.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.